package string;

public class StringBuildDemo {
    public static void main(String[] args) {
        /*StringBuilder builder1 = new StringBuilder();
        StringBuilder builder2 = new StringBuilder("abc");
         String str="abc";
         StringBuilder builder3=new StringBuilder(str);
         String str2=builder3.toString();

         */
         String str="好好学习Java";
        StringBuilder builder = new StringBuilder(str);

         builder.append(",为了找个好工作");
        System.out.println(builder);

        builder.replace(9,16,"就是为了改变世界");
        System.out.println(builder);

        builder.delete(0,8);
        System.out.println(builder);

        builder.insert(0,"活着");
        System.out.println(builder);

    }
}
